feat: dual-station radar track plot (satlover/satmatch style)

- MutualPass now carries TrackSample (azimuth/elevation for both stations)
- New MutualRadarView: polar plot with elevation rings (30/60/90),
  cardinal spokes, solid A-track vs dashed B-track, AOS/LOS markers
- Shown in expanded mutual pass card and radar page mutual card

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/repository/IMainContainer.kt

@@ -46,6 +46,7 @@ interface IMainContainer {
 
 data class MutualPassData(
     val samples: List<Pair<Long, Pair<Double, Double>>> = emptyList(),
+    val trackSamples: List<TrackSampleData> = emptyList(),
     val startTime: Long = 0L,
     val endTime: Long = 0L,
     val maxElev: Double = 10.0,
@@ -53,6 +54,14 @@ data class MutualPassData(
     val labelB: String = "友台"
 )
 
+/** Minimal track sample for cross-module sharing (angles in degrees). */
+data class TrackSampleData(
+    val azimuthA: Double,
+    val elevationA: Double,
+    val azimuthB: Double,
+    val elevationB: Double
+)
+
 interface IContainerProvider {
     fun getMainContainer(): IMainContainer
 }